Indicator apparatus



Nov. 26, 1968 Fig. 1 :3

Filed Aug. 23, 1965 W. M. CAREY ETAL.

INDICATOR APPARATUS CODING sw1'rc11 a a 7 e 5 4 a 2 1 o 1 1 I 1 1 1 1 ll l I 18\--' '9 12 11 11 11 11 11 11 11 I 1 V 1 1 1 1 1' 1- rl J1 1| I[I 1' Al ll II III 10 C) (T (9 Al F 5g 2 INVENTORS AC 433%? 215F511 M KJR. SUPPLY BY ATTORNEY United States Patent 3,413,631 INDICATORAPPARATUS William M. Carey, Sonth Lincoln, and Thomas E. Baker,

Jr., Framingham, Mass., assignors, by mesne assignments, to the UnitedStates of America as represented by the Secretary of the Navy Filed Aug.23, 1965, Ser. No. 481,992 6 Claims. (Cl. 340-336) ABSTRACT OF THEDISCLOSURE An alphanumeric indicator comprising a plurality ofmultiaperture devices (or transfluxors) which selectively energize anarray of lamps in accordance with a digital input signal. A codingswitch pulses one of a plurality of conductors each forming seriallyconnected windings at selected major aperture of its respectivetransfluxor. The conductors are then connected in common to one end ofanother conductor which forms serially connected windings at the minoraperture of each transfiuxor, and which is connected to ground at theother end. The number of turns in the major aperture winding is greaterthan the number of turns in the minor aperture windings. An outputwinding at the minor aperture of each transfiuxor is connected to arespective lamp and to a common power supply.

The present invention relates to apparatus for the display or indicationof alphabetical or numerical symbols, and more particularly to a highspeed decoding and memory apparatus for selectively operating lamps inan array suitable for displaying alphabetical or numerical symbols.

Presenting digital information in directly readable form to an operatoris usually an expensive and, in terms of computer timing, a slowprocess. Commercially available devices such as electromagneticelements, gas storage tubes, or a complete array of electronic equipmentare either slow, unreliable or expensive. Some of these devices are alsoheavy power drains on the computers associated therewith.

Briefly, the present invention contemplates a plurality ofmulti-aperture devices (MAD), also known as transfiuxors, whichselectively energize an array of lamps in accordance with a digitalinput signal. Each MAD acts as a variable impedance in series with alamp, and by applying a pulse of current through selected MADs, therespective lamps illuminate. The result is an apparatus which decodes,memorizes, and indicates in alphabetical or numerical symbols thedigital input signal in a response time of less than 20 microseconds.The memory and high speed features, in particular, greatly simplify thedesign and reduce the hardware requirements of the associated computers.

Accordingly, it is an object of the present invention to provide a noveland improved apparatus for the indication of alphabetical or numericalsymbols, in which digital input signals representing the symbols aredecoded and memorized, and which is especially suitable for displayingdigital information from computers.

Another object of the invention is to provide a novel circuit means foroperating a plurality of multiple aperture devices capable of decodingand memorizing digital information.

Still another object of the invention is to provide an improved alpha ornumeric indicator apparatus which is relatively inexpensive tomanufacture and maintain, which is reliable and has relatively fastresponse, and which is not subjected to the operational limitations ofthe prior art devices.

Various other objects and advantages will appear from the followingdescription of one embodiment of the invention, and the most novelfeatures will be particularly pointed out hereinafter in connection withthe appended claims.

In the drawing:

FIG. 1 pictorially represents a typical array of elongated lampssuitable for indicating alphabetical or numerical symbols;

FIG. 2 is a schematic wiring diagram of one embodiment of the presentinvention as applied to the array of FIG. 1; and

FIG. 3 is a more detailed schematic diagram of one multi-aperture deviceas applied to the embodiment of FIG. 2.

Referring now to the illustrated embodiment of the invention, FIG. 1shows a numerical indicator 10 which includes seven elongated electricallamps identified by the letters A through G, and which are arranged todisplay any of the digits 0 through 9 depending on which combination oflamps are illuminating. For example, the number 1 requires illuminationof lamps B and E; number 2, lamps A, B, C, G and F; and number 3, A, B,C, E and F. As will become apparent, it is contemplated that the numberof lamps can be changed or their arrangement modified for displayingmany other symbols without departing from the inventive concepts.

The manner in which the indicator 10 is operated is best described byreference to FIGURE 2 in which the lamps A through G are convenientlyshown as a row of filaments. Each lamp is associated in a circuit to bedescribed, with a MAD (multi-apertured device) 11 of the type having onemajor and one minor aperture, 12 and 13, respectively. There being sevenlamps in the illustrated embodiment of the invention, there aretherefore seven MADs. A more detailed disclosure of the two-aperture MAD(a transfiuxor) appears in the article The Transfluxor by J. A. Rajchmanet al., Proceedings of the I.R.E., vol. 44, March 1956, pp. 321332.

Each MAD 11 is connected to its respective lamp A. B, C, etc. by a wire14 threaded once through the minor aperture of the MAD and connected atone end to one terminal of the lamp filament. The other end of each wire14 is connected in common to one output terminal of an AC. supply 15,and the other terminal of each lamp filament is connected in common toanother output terminal of the supply 15. The supply 15 may be of anyconventional design capable of generating an alternating current; forexample, a free-running blocking oscillator.

The major aperture of each MAD 11 receives up to ten parallel-connectedwires from a coding switch 16, each wire representing a discrete symbolof 0 through 9. The total number of wires from the switch 16, of course,will be equal to the number of symbols subject to indication by theindicator 10. The coding switch 16 may be of any conventional type whichgenerates a short (e.g. 1O microseconds) pulse of current at one of aplurality of output terminals in accordance with a command input signal(not shown). Each output terminal is assigned to represent a discretesymbol (alphabetical, numerical, etc.) indicative of the input signal.

For convenience of illustration, only three wires 17, 18 and 19 havebeen drawn which connect to the 0, 7 and 8 terminals of the switch 16.These wires serially pass through only selected major apertures of the.MADs 11 depending on which of the lamps A through G must be illuminatedto indicate the corresponding number. For example, a current pulse atthe output terminal 0 of the switch 16 must energize all but lamp C.Accordingly, the wire 17 must serially pass through all of the majorapertures except the one associated with lamp C. Similarly, wire 18passes through only the major apertures associated with lamps A, B andE; and wire 19 passes through all of the major apertures. The wires fromthe switch 16 are connected in common to one end of a wire 21 beyondwhere all of the selected major apertures have been threaded. The wire21 passes through all of the minor apertures and is connected to groundat its other end. Thus, whenever a current pulse appears on any wirepassing through the selected major apertures, the same pulse appears atall the minor apertures. The resulting operation is that whenever apulse from the switch 16 appears at both the major and minor apertures,the impedance in wire 14 becomes low, and the associated lampilluminates. If the pulse only appears at the minor aperture, theimpendance in wire 14 becomes high, and the associated lampextinguishes.

The theory of this operation is best explained in connection with theMAD 11 associated with lamp D as shown in more detail in FIG. 3. Wherethe wires 17, 14 and 21 pass through the MAD apertures, they will nowcalled windings W W and W respectively, as in fact they are. A currentpassing through any winding will impart a magnetomotive force in itsadjacent aperture. Thus, when a heavy current pulse from coding switch16 is sent through the winding W sufiicient to switch the field fluxabout the major aperture and in a direction to produce counterclockwisesaturating fluxes (p and the MAD becomes blocked. In this condition, analternating current through the winding W in the minor aperture isinsufiicient to switch the flux qfl or about the minor aperture. Themagnetmotive .force of winding W will encounter no opposition andmanifest itself as a low impedance in winding W This low impedance inwinding W orwire 14 impresses a high voltage across the lamp D whichcauses it to illuminate.

Now, if another heavy current pulse is sent through the winding Wsufiicient to switch the saturated flux qb about the minor aperture andin a direction to produce clockwise flux, the MAD 11 becomes unblocked.No amount of current of either polarity through the winding W or W candrive the MAD back to the blocked condition. Only another heavy currentpulse in the winding W can do this. It is this property which providesthe memory feature.

In the unblocked condition, a relatively low amplitude alternatingcurrent applied to winding W will produce a changing flux offeringthereby a high impendance in the winding W A low voltage thereforeappears across the lamp D and causes it to become extinguished.

The winding W has two turns through the major aperture as compared toone in winding W to insure blocking of the MAD 11 even though the samecurrent pulse passes through both windings. Where a MAD has no winding Wthe winding W will unblock.

It should now be apparent that the utilization of multiaperture devicesas variable impedances in an electrical circuit responsive to digitalinput signals may be used to selectively energize any plurality of lampsor other electrical components. Except for the power required toenergize the lamps, the only other power required is for initiating andmaintaining selection, and this requirement is extremely low. This isdue to the inherent memory characteristics of the MAD inasmuch as nopower is required after the initial pulse to maintain the selection. Thesystem is automatically reseting when another pulse is impressed at theinput; and the inherent high speed response characteristics makes itideally suited for high speed computer applications.

It will be understood, of course, that various changes in the details,materials, steps and arrangement of parts, which have been hereindescribed and ilustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims.

What is claimed is:

1. Apparatus for decoding and memorizing information comprising:

a decoding switch having a plurality of output terminals for selectivelyproducing a digital output signal, each of said terminals representing adiscrete symbol;

a plurality of multi-apertured devices, each having a major and a minoraperture,

a plurality of first conductor means, each connected at one end torespective output terminals of said switch, and forming seriallyconnected windings through predetermined major apertures of saiddevices, and connected in common at the other end to each other; and

second conductor means connected at one end to said common connection,and forming serially connected windings through all of said minorapertures, and connected at the other end to ground, the number of turnsin the windings of said first conductor means being greater than thewindings of said second conductor means.

2. Apparatus as comprising:

a plurality of electrical loads;

a plurality of third conductor means each connected at one end to oneterminal of respective loads, passing through the minor aperture of arespective device, and connected in common at the other end to eachother; and

alternating current supply means having two output terminals connectedrespectively to the common connection of said third conductors and theother terminals of said loads.

3. Apparatus as set forth in claim 2 wherein said device produces highimpedance in said third conductor means when a pulse of current passesthrough said first conductor means of said major apertures.

4. Apparatus as set forth in claim 3 wherein said device produces a lowimpedance in said third conductor means when a pulse of current passesthrough said second conductor means.

5. Apparatus as set forth in claim 4 wherein said plurality ofelectrical loads comprise electric lamps arranged in an array forindicating the discrete symbols in accordance with which of theterminals of said switch is energized.

6. Apparatus as set forth in claim 1 wherein the number of turns in thewindings of said first conductor means are at least twice the number ofturns in the windings of said second conductor means.

set forth in claim 1 further References Cited UNITED STATES PATENTS3,329,829 7/1967 Grimm et al 340-174 3,357,010 12/1967 Sweeney 340-324OTHER REFERENCES Rajchman et al.: The Transfiuxor IRE Proceedings, pp.321-332, March 1956.

Rajchman et al.: Transfiuxor Controlled E-L Display Panels, IREProceedings, pp. 1808-1824, November 1958.

JOHN W. CALDWELL, Primary Examiner.

A. J. KASPER, Assistant Examiner.

